Diet change likely to drive crocodile population boom: Australian study-Xinhua

Diet change likely to drive crocodile population boom: Australian study

Source: Xinhua

Editor: huaxia

2022-04-28 11:14:18

CANBERRA, April 28 (Xinhua) -- A change in the diet of crocodiles from seafood to pork could be responsible for the population boom of the species in Australia's Northern Territory.

A study published by Charles Darwin University (CDU) on Wednesday has revealed evidence that a shift in diet away from seafood towards land-based animals is a major factor in the exponential population growth.

Since the 1970s, the number of saltwater crocodiles in the Northern Territory has grown from an estimated 3,000 to approximately 100,000.

The research team compared bone samples from crocodiles that were killed about half a century ago to those of modern crocodiles, finding the changing diet has coincided with growing crocodile numbers.

Mariana Campbell, co-author of the study, said dietary changes could also be contributing to the increased movement of the Northern Territory's crocodiles into floodplains where there are more feral pigs.

"We were surprised to observe such a significant shift in the diet of estuarine crocodiles across the Top End over the past 50 years," she said in a media release.

"Our results show that they have shifted from a marine-estuarine based diet, such as fish, marine turtles, to a more terrestrial based diet of feral pigs, and buffalo."

Hunting saltwater crocodiles was banned in the Northern Territory in 1971 with the iconic species facing extinction.

Campbell said its recovery ever since made it Australia's largest carnivore success story.

"A reduction in estuarine prey may have also contributed to the crocodile's diet change," she said. "It is likely a combination of a change in available prey, and a general ingress of crocodiles from the estuaries into the freshwater flood plains."